Some traditional portable electronic devices allow users to generate sounds (e.g., software that allows a user to play a basic synthesizer on his phone), but such devices include no functionality for coordinating sound generation across multiple devices and users. For example, a traditional portable electronic device may allow a user to play a musical piece on her device, but the device will not coordinate her music with any other devices or their users. Some performers have applied manual coordination techniques (e.g., a human conductor standing in front of all of the performers), but these techniques fail to exploit any of the added functionality provided by an electronic device as opposed to a traditional musical instrument.